After four years of veterinary school, I (Dr. Perry Jameson) decided that instead of going straight into practice, I'd continue learning and do an internship and residency.
During these years, I saw many diseases for the first time in real patients rather than just a description in a text book or lecture. For me, many of my patients obviously did not read the text book, as they presented with symptoms for diseases I was not taught.
I remember one such case well.
There was an older dog, Shep, I had hospitalized in the ICU at the University of Georgia for renal failure. He was responding to his therapy and I had been discussing with his parents when he should go home. That is why I was surprised when my pager went off calling me to ICU, STAT. The nurses informed me he was having a seizure.
When I looked into his kennel, that is what he looked like to me, too. He was violently rolling in one direction and could not stop. When we tried to stop him, he would twist his head in the same direction he was rolling.
I was worried this was another major problem that would be the end of his life. I called Dr. John Oliver to get his advice; he was a neurologist who wrote the textbook by which many of us were taught neurology.
He got down on the floor and began examining Shep. After about 2 minutes, he stood up and informed me that Shep would be OK. He had what is commonly called "old dog" vestibular disease. Oliver explained that it is basically like a bad case of vertigo; dogs feel like they are spinning and may even get nauseated. Usually over the next five to seven days the symptoms resolve, however, some may have a permanent mild head tilt.
Over the years, I have seen this syndrome so many times. Pet parents rush in often thinking their pet has had a stroke or even worse, a brain tumor. It is nice being able to tell them their pet has a disease that at first looks terrible but from which they can fully recover.
Cats may develop this condition, as well.
The vestibular system is the part of the nervous system responsible for keeping your pet oriented with respect to gravity. It helps maintain the position of the eye, body and limbs in relationship with the position of the head. Balance, head orientation and eye movements are all affected by a disturbance anywhere in the vestibular system.
The vestibular system is divided into two areas: peripheral and central. A simple way to think of the difference is that central disease affects the brain and brain stem while peripheral diseases affect the inner ear or nerves connecting it to the brainstem.
It is important to differentiate between the two locations as centrally located diseases usually carry a more guarded prognosis. Your veterinarian can perform a neurological examination to help differentiate the two.
The most common peripheral vestibular diseases are an inner ear infection, idiopathic vestibular disease (also called "old dog" vestibular disease), ototoxins, congenital vestibular disease, tumors and trauma.
Causes of central vestibular disease are tumors, inflammation or infection, hypothyroidism and toxins.
Clinical symptoms of Vestibular disease are:
Head tilt to the affected side
Nystagmus (fast twitch of the eyes)
Strabismus (abnormal eye position)
Falling or rolling to the affected side
Nausea, vomiting, anorexia
If your pet presents with vestibular disease, the first thing done is a neurologic examination to help differentiate central from peripheral location. Tell your veterinarian all medications your pet is on so they can determine if any could cause the problem.
A thorough otoscopic (ear) examination is always indicated to determine if an outer ear infection has spread deeper.
A complete physical examination is done to look for evidence of systemic disease like infection, tumors and hormonal diseases.
Blood samples can be submitted to assess for hypothyroidism and tick-transmitted diseases known to cause vestibular disease.
If a middle ear infection is suspected to have spread to the inner ear, samples can be collected through the ear drum for culture and cytology.
An MRI provides the most detailed pictures of the brain, middle ear and inner ear. CT and radiographs can provide some information but are not as detailed as a MRI. If inflammation of the brain or brain stem is suspected, this can be confirmed by obtaining fluid with a cerebrospinal fluid tap.
Treatment is based on the underlying cause if one is identified. For idiopathic disease, like Shep had, we treat with supportive care until the symptoms resolve. This often includes anti-motion sickness and anti-nausea medications.
There are multiple causes for abnormalities of the balance center in dogs and cats, and a thorough physical and neurologic exam can help differentiate. Despite being an older dog like my patient Shep, it may not be a terminal problem like a brain tumor but could be a condition that with a few days of TLC they can recover from completely.